How to update the PI Tags value using AFSDK and PISDK?
Yes, the forums contain many useful information and you will likely get your questions answered by searching through the forums.
To get you started:
PI SDK (please refer to the programming help file installed on your PI SDK machine at %pihome%\HELP\pisdk.chm):
This blog post also contains some code snippets:
Write Value to Multiple Tags or Attributes
Have you tried searching the forums?
Retrieving data ...